Steps/methods:
Pregnant women, at this time, have a second life in their bodies. The body is in a very weak state. To whiten teeth, chemicals are usually used to whiten teeth, or objects are attached to teeth to cover black teeth. Chemicals that enter the body through the mouth are undoubtedly harmful to children. Never get pregnant and whiten your teeth.
And adolescent children under 16 can't whiten their teeth. During adolescence, the body is in a state of development, including bones and teeth. Doing tooth whitening rashly is harmful to development. It is best to wait until adulthood to consider whitening teeth.
There are also some serious tetracycline teeth and dental fluorosis. If you have periodontitis or enamel dysplasia, don't whiten your teeth. This kind of people's tooth whitening will not only bring them toothache, but also have no obvious effect even after tooth whitening. It is recommended not to do it.